function s1_generate_a_series_files(){
   for i in {1..100}; do
       echo $i>/tmp/new_file$i;
    done
}

function s2_list_4_files_in_long_format_about_account_and_group(){
       ls -l /etc/{passwd,shadow,group,gshadow} |sort -d
}

function s3_find_items_related_to_given_username(){
   grep -h $1 /etc/{passwd,shadow} |sort -d
}

function s4_find_items_related_to_given_group_name(){
          grep -h $1 /etc/{group,gshadow} |sort -d
}

function s5_create_groups_for_given_group_names(){
  local groups=("rnd" "itoperation")
  for group in "${groups[@]}"; do
      groupadd "$group"
  done
}

function s6_create_users_and_set_their_group_as_required(){
   users=("adam" "bob" "calvin" "david" "edward")
   primary_groups=("users" "users" "users" "users" "users")
   supplementary_groups=("rnd" "rnd" "itoperation" "itoperation" "rnd")

   for i in "${!users[@]}"; do
       useradd -g "${primary_groups[$i]}" "${users[$i]}"
       usermod -aG "${supplementary_groups[$i]}" "${users[$i]}"
   done
}

function s7_change_users_shell(){
   users=("adam" "edward")
   for user in "${users[@]}"; do
       usermod -s /usr/bin/sh "$user"
   done
}

function s8_set_password_change_policy(){
    local usernames=("adam" "bob" "calvin" "david" "edward")
    for username in "${usernames[@]}"; do
        chage -M 60 -m 10 -W 10 "$username"
    done
}

function s9_set_password_for_five_users(){
   usernames=(adam bob calvin david edward)
for i in $(seq 1 5); do 
echo $(( $i-1 ));done
echo "${usernames[0]}:$1" | chpasswd
echo "${usernames[1]}:$2" | chpasswd
echo "${usernames[2]}:$3" | chpasswd
echo "${usernames[3]}:$4" | chpasswd
echo "${usernames[$(( $i-1 ))]}:$5" | chpasswd

}

function s10_lock_bobs_password(){
passwd -L bob
}

function s11_include_adam_into_wheel_group(){
usermod -a -G wheel adam
}

function s12_change_files_permission(){
for i in {1..33}; do
chmod -R 640 /tmp/new_file$[3*i];
done
}



